Moisture remains a hot-button topic in the industry, and it shows no signs of becoming less of an issue anytime soon. For our annual Moisture Mitigation Case Studies feature, we spoke with contractors from around the country to find out how they deal with moisture problems while on the job. They also share what products they use when encountering these issues.
Glynn Nickerson, owner of Advanced Wood Floors in San Antonio, sees moisture as an increasing problem for the industry. “I think the manufacturers have created the issue for us installers, because everything gets pushed back on us. We’re the ones taking the brunt of the hit whenever there’s a problem,” he stated.
He prefers putting down a moisture barrier whenever possible because “the liability if the floor fails will come back to us 100%. If we go into a home and educate the homeowners that we need to do a moisture test and will need to use a moisture barrier, they usually understand. Homebuilders, however, will fight us over it.”
Nickerson’s go-to products are Titebond 531 two-part epoxy and Bostik MVP4 Moisture Vapor Protection, Anti-Fracture and Noise Reduction Membrane. He also has had Uzin Utz North America demonstrate some of their moisture barriers for him, but he hasn’t had the opportunity to use it in the field yet.
Nickerson said the most important step to working with a moisture vapor barrier is “read the directions as closely as you possibly can. For example, with the MPV4 as long as you’re not wiping water off the floor there’s no testing necessary. But not all of them are like that, so it’s important to read through the directions.”
Raymond Miller, installation manager for Halpin’s Flooring America in Baton Rouge, said moisture has always been an issue in his region. “Down here in Louisiana we have real moist soil. I’ve done jobs where at first there’s nothing and then people have moisture problems all of a sudden.”
He recalls a recent job where a homeowner went with a competitor to install 7 in. wide, engineered hand-scraped hickory, and ended up eating $15,000 for their troubles. “About a year after the installation, discoloration popped up all over the floor. Of course they can’t find the installer that put it in, and he didn’t do any moisture readings or tests.”
To fix the problem, Miller removed the floor, let the area air out for a few days, then encapsulated it with DriTac 7000 Premium Green Concrete Moisture Control System.
“After that, we installed a new hand-scraped hickory floor with DriTac 7800 Supreme Green wood flooring adhesive,” he noted. “Now the installation is basically bulletproof, and I don’t anticipate any more issues.”
According to Peter Schurkman, owner of JKP Flooring in Anaheim, Calif., moisture issues are increasing in his area. To help protect himself from liability, he has moisture tests completed by an independent third party. “That way there’s no conflict,” he said.
The moisture control products he uses the most are Kovara and Kovara MBX rolled membrane from GCP Applied Technologies. “We do a lot of occupied offices, and Kovara is easy to get underneath the furniture, easy to cut, and really it’s just cleaner and easier for those office settings,” he said.
Having encountered moisture issues frequently in the field, Schurkman has developed an instinct for when moisture is an obvious problem. “If there’s a hard surface on the floor like vinyl or rubber, you can often see bubbling within it or a white calcium buildup in the seams. Sometimes you’ll see black adhesive coming up through the seams. Sometimes there’s even a little bit of an odor.”
He sees one main culprit leading to most of the moisture problems. “The biggest issue is hydrostatic pressure, which means the moisture in the ground is drawn up almost like a vacuum when you cover it with a slab. And then it doesn’t have a chance to breathe when you cover that slab over with a hard surface.”
Kirk Dalton, head of the specialty cements and applied coatings division of Welker Bros. in Milpitas, Calif., said moisture mitigation is an everyday issue. “The construction industry is trying to drop their time limit to a third of what it used to be. New projects are getting done long before the concrete has even cured enough to where moisture wouldn’t be an issue. Almost every contractor worth their salt will put some sort of allowance for moisture mitigation [in their bid].”
According to Dalton, common issues that contribute to moisture problems include “whether or not a building has a vapor system under the slab, and whether too much water was used in the mixing of the concrete. Often, we’re dealing with what’s called ‘convenience water.’ It takes very little water to make concrete, and a little more water to make it workable. However, it takes a long time for that little bit of extra water to get out of there.”
He said that almost all of the flooring he puts down requires some kind of vapor system “because of the fast-track projects out there right now.”
Dalton added,” We needed a product that’s moisture and pH insensitive, with a really good cement system at a minimum of 1/8 in. on top of it to allow adhesives to grab into it. I use three products from Custom Building Products all the time for just this situation.”
The three products he uses are CustomTech’s TechMVC Moisture Vapor and Alkalinity Barrier, TechLevel 150 self-leveling underlayment and the company’s TechPrime primer.
He stressed that proper moisture mitigation comes down to surface prep. “No matter what anybody tells you, you’ve got to prep that floor or your chance of success is limited. If they tell you it’s a no-prep product, don’t listen.”
Mark Sutherland, co-owner of Valley Lake Flooring in Apple Valley, Minn., said moisture problems have increased over the last decade. “When the government came in and made manufacturers change their formulas for fewer VOCs, they switched to more water-based products. In my opinion, that created a lot of the moisture problems we have today.”
He noted that moisture testing does help give a picture of a slab’s moisture level, but there are limitations. “A lot of people don’t seem to understand that whether you do a calcium chloride test or RH test, it’s only as good as the time you do the testing in. Also, you’re supposed to be in a controlled environment when the tests are occurring. That doesn’t happen very often.”
He recommended that contractors always let a third party handle moisture tests. “If you do your own testing, it will not hold up in a court of law—if a floor fails and you walk into court, the first question they’re going to ask is ‘Are you certified to do these tests?’ If you’re not, you just bought the job.”
One major cause of failures is improperly prepared concrete, Sutherland stated. “Concrete should be prepped, with a shot blaster—not a planetary grinder because you can’t open up the pores of the concrete on a consistent basis. We shot blast everything and grind the edges. A shot blaster follows the contours of the concrete to open it up the way it should be open.”
He added, “Every time I shot blast a floor, we do a water test. We add droplets of water to the concrete to see if it penetrates in less than a minute. If water doesn’t permeate the concrete, what makes you think epoxy is going to permeate it?”
One of the products that has become a workhorse for Sutherland is EPA Rapid from Schönox HPS North America. “The reason why I use it is because it gives me a quicker turnaround time,” he said.
“We also always recommend at least 1/8 in. of cementitious material on top of the barrier,” he added. “Why? Well, what do people do every 8-15 years? They renovate. If you have that cementitious layer down, they won’t destroy the moisture mitigation system underneath.”